SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6e2683bdfe83beac27df58367988b487757a881f359171612b4680cf8e11950' 
  AND token = '44ncfb6YY5TxfUTcSE5rftIgPxmO7pZj2GUHIypGNLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}